Delhi air quality ‘very poor’, may improve slightly today
Delhi’s air quality on Monday touched very poor levels, readings of the System of Air Quality and Weather Forecasting and Research (SAFAR) showed.
Experts say wind speed is the reason behind the increase in pollution levels. Forecasts, however, say the air quality will improve slightly on Tuesday.
On Monday, the overall Air Quality Index read 304, which is “very poor”. In terms of individual stations, Noida had the highest AQI 336, followed by Mathura Road 324, Dhirpur 313, Delhi University 307 and Pitampura recorded 305.
As per the SAFAR advisory, people with existing heart or lung diseases must avoid exertion when the air quality is “very poor”.
The 24-hour rolling average of PM2.5 also touched very poor at 125 microgram per cubic metre, respectively. For PM10, it was moderate clocking 247 microgram per cubic metre.
PM2.5 and PM10 are ultrafine particles that are the dominant pollutants in Delhi. The 24-hour acceptable levels of PM 2.5 and PM10 are 60 and 100 microgram per cubic metre, respectively.
Dipankar Saha, additional director and head of the air laboratory at the Central Pollution Control Board, said this foul air quality is due to low wind speed in the city.
“The main factors that influence Delhi’s air quality are wind speed and direction. Whenever surface wind speed decreases, pollution levels shoot up. The wind speed on Monday is 1 metre per second. Such low wind speed increases chances of accumulation of pollutants,” Saha told HT.
Delhi, a city of about 20 million people, is among the world’s most polluted according to the World Health Organisation. It has been struggling to clean up a toxic cocktail of dust, smoke and gases from its air.
According to an IIT Kanpur report on pollution sources of the city, in summer, coal and fly ash, soil and road dust, secondary particles, biomass burning, vehicles and municipal solid waste burning are the reason behind the foul air. However, in summers, high wind speed usually ensures less air pollution compared to winter.